diff --git a/.dockerignore b/.dockerignore
index 32e6c2a0cd..d1ad0ba8e0 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -4,7 +4,8 @@
 # Except proxy
 !proxy
 !requirements.txt
-!setup.py
+!pyproject.toml
+!setup.cfg
 !README.md
 
 # Ignore __pycache__ directory
diff --git a/.github/workflows/test-library.yml b/.github/workflows/test-library.yml
index c349ef7857..f35d21019c 100644
--- a/.github/workflows/test-library.yml
+++ b/.github/workflows/test-library.yml
@@ -26,8 +26,8 @@ jobs:
           pip install -r requirements-tunnel.txt
       - name: Quality Check
         run: |
-          flake8 --ignore=W504 --max-line-length=127 --max-complexity=19 proxy/ tests/ setup.py
-          mypy --strict --ignore-missing-imports proxy/ tests/ setup.py
+          flake8 --ignore=W504 --max-line-length=127 --max-complexity=19 proxy/ tests/
+          mypy --strict --ignore-missing-imports proxy/ tests/
       - name: Run Tests
         run: pytest --cov=proxy tests/
       - name: Upload coverage to Codecov
@@ -37,6 +37,82 @@ jobs:
       - name: Integration testing
         if: matrix.os != 'windows'
         run: |
-          python setup.py install
+          pip install .
           proxy --hostname 127.0.0.1 --enable-web-server --pid-file proxy.pid --log-file proxy.log &
           ./tests/integration/main.sh
+
+  tox:
+    name: ${{ matrix.toxenv }}
+
+    runs-on: Ubuntu-latest
+    strategy:
+      matrix:
+        toxenv:
+        - cleanup-dists,build-dists,metadata-validation
+      fail-fast: false
+
+    env:
+      PY_COLORS: 1
+      TOX_PARALLEL_NO_SPINNER: 1
+      TOXENV: ${{ matrix.toxenv }}
+
+    steps:
+    - name: Switch to using Python v3.10
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.10'
+    - name: >-
+        Calculate Python interpreter version hash value
+        for use in the cache key
+      id: calc-cache-key-py
+      run: |
+        from hashlib import sha512
+        from sys import version
+
+        hash = sha512(version.encode()).hexdigest()
+        print(f'::set-output name=py-hash-key::{hash}')
+      shell: python
+    - name: Get pip cache dir
+      id: pip-cache
+      run: >-
+        echo "::set-output name=dir::$(pip cache dir)"
+    - name: Set up pip cache
+      uses: actions/cache@v2.1.5
+      with:
+        path: ${{ steps.pip-cache.outputs.dir }}
+        key: >-
+          ${{ runner.os }}-pip-${{
+          steps.calc-cache-key-py.outputs.py-hash-key }}-${{
+          hashFiles('tox.ini') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-${{
+              steps.calc-cache-key-py.outputs.py-hash-key
+          }}-
+          ${{ runner.os }}-pip-
+    - name: Install tox
+      run: >-
+        python -m
+        pip install
+        --user
+        tox
+
+    - name: Grab the source from Git
+      uses: actions/checkout@v2
+
+    - name: >-
+        Pre-populate tox envs: `${{ env.TOXENV }}`
+      run: >-
+        python -m
+        tox
+        --parallel auto
+        --parallel-live
+        --skip-missing-interpreters false
+        --notest
+    - name: >-
+        Run tox envs: `${{ env.TOXENV }}`
+      run: >-
+        python -m
+        tox
+        --parallel auto
+        --parallel-live
+        --skip-missing-interpreters false
diff --git a/Dockerfile b/Dockerfile
index 29292e22ea..4c176f8c0d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,7 +2,8 @@ FROM python:3.10-alpine as base
 FROM base as builder
 
 COPY requirements.txt /app/
-COPY setup.py /app/
+COPY pyproject.toml /app/
+COPY setup.cfg /app/
 COPY README.md /app/
 COPY proxy/ /app/proxy/
 WORKDIR /app
diff --git a/Makefile b/Makefile
index e0331a5ece..f165b9a288 100644
--- a/Makefile
+++ b/Makefile
@@ -30,7 +30,6 @@ autopep8:
 	autopep8 --recursive --in-place --aggressive examples
 	autopep8 --recursive --in-place --aggressive proxy
 	autopep8 --recursive --in-place --aggressive tests
-	autopep8 --recursive --in-place --aggressive setup.py
 
 https-certificates:
 	# Generate server key
@@ -90,14 +89,14 @@ lib-clean:
 	rm -rf .hypothesis
 
 lib-lint:
-	flake8 --ignore=W504 --max-line-length=127 --max-complexity=19 examples/ proxy/ tests/ setup.py
-	mypy --strict --ignore-missing-imports examples/ proxy/ tests/ setup.py
+	flake8 --ignore=W504 --max-line-length=127 --max-complexity=19 examples/ proxy/ tests/
+	mypy --strict --ignore-missing-imports examples/ proxy/ tests/
 
 lib-test: lib-clean lib-version lib-lint
 	pytest -v tests/
 
 lib-package: lib-clean lib-version
-	python setup.py sdist
+	python -m tox -e cleanup-dists,build-dists,metadata-validation
 
 lib-release-test: lib-package
 	twine upload --verbose --repository-url https://test.pypi.org/legacy/ dist/*
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000000..62b4b846b0
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,6 @@
+[build-system]
+requires = [
+  # Essentials
+  "setuptools",
+]
+build-backend = "setuptools.build_meta"
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000000..0beefb22ee
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,114 @@
+[metadata]
+name = proxy.py
+version = attr: proxy.common.version.__version__
+url = https://github.com/abhinavsingh/proxy.py
+download_url = https://github.com/abhinavsingh/proxy.py/archive/develop.zip
+description =
+  ⚡⚡⚡Fast, Lightweight, Pluggable, TLS interception capable proxy
+  server focused on Network monitoring, controls & Application development,
+  testing, debugging.
+long_description = file: README.md
+long_description_content_type = text/markdown
+author = Abhinav Singh
+author_email = mailsforabhinav@gmail.com
+license = 'BSD'
+license_files =
+  LICENSE.md
+classifiers =
+  Development Status :: 5 - Production/Stable
+
+  Environment :: Console
+  Environment :: No Input/Output (Daemon)
+  Environment :: Web Environment
+  Environment :: MacOS X
+  Environment :: Plugins
+  Environment :: Win32 (MS Windows)
+
+  Framework :: Robot Framework
+  Framework :: Robot Framework :: Library
+
+  Intended Audience :: Developers
+  Intended Audience :: Education
+  Intended Audience :: End Users/Desktop
+  Intended Audience :: System Administrators
+  Intended Audience :: Science/Research
+
+  License :: OSI Approved :: BSD License
+
+  Natural Language :: English
+
+  Operating System :: MacOS
+  Operating System :: MacOS :: MacOS 9
+  Operating System :: MacOS :: MacOS X
+  Operating System :: POSIX
+  Operating System :: POSIX :: Linux
+  Operating System :: Unix
+  Operating System :: Microsoft
+  Operating System :: Microsoft :: Windows
+  Operating System :: Microsoft :: Windows :: Windows 10
+  Operating System :: Android
+  Operating System :: OS Independent
+
+  Programming Language :: Python :: Implementation
+  Programming Language :: Python :: 3 :: Only
+  Programming Language :: Python :: 3
+  Programming Language :: Python :: 3.6
+  Programming Language :: Python :: 3.7
+  Programming Language :: Python :: 3.8
+  Programming Language :: Python :: 3.9
+  Programming Language :: Python :: 3.10
+
+  Topic :: Internet
+  Topic :: Internet :: Proxy Servers
+  Topic :: Internet :: WWW/HTTP
+  Topic :: Internet :: WWW/HTTP :: Browsers
+  Topic :: Internet :: WWW/HTTP :: Dynamic Content
+  Topic :: Internet :: WWW/HTTP :: Dynamic Content :: CGI Tools/Libraries
+  Topic :: Internet :: WWW/HTTP :: HTTP Servers
+
+  Topic :: Scientific/Engineering :: Information Analysis
+
+  Topic :: Software Development :: Debuggers
+  Topic :: Software Development :: Libraries :: Python Modules
+
+  Topic :: System :: Monitoring
+  Topic :: System :: Networking
+  Topic :: System :: Networking :: Firewalls
+  Topic :: System :: Networking :: Monitoring
+
+  Topic :: Utilities
+
+  Typing :: Typed
+keywords =
+  http
+  proxy
+  http proxy server
+  proxy server
+  http server
+  http web server
+  proxy framework
+  web framework
+  Python3
+
+[options]
+python_requires = >= 3.6
+packages = find:
+include_package_data = True
+zip_safe = False
+
+# These are required in actual runtime:
+install_requires =
+  typing-extensions; python_version < "3.8"
+
+[options.entry_points]
+console_scripts =
+  proxy = proxy:entry_point
+
+[options.package_data]
+proxy =
+  py.typed
+
+[options.packages.find]
+exclude =
+  tests
+  tests.*
diff --git a/setup.py b/setup.py
deleted file mode 100644
index 45ec2d5454..0000000000
--- a/setup.py
+++ /dev/null
@@ -1,105 +0,0 @@
-# -*- coding: utf-8 -*-
-"""
-    proxy.py
-    ~~~~~~~~
-    ⚡⚡⚡ Fast, Lightweight, Programmable, TLS interception capable
-    proxy server for Application debugging, testing and development.
-
-    :copyright: (c) 2013-present by Abhinav Singh and contributors.
-    :license: BSD, see LICENSE for more details.
-"""
-from setuptools import setup, find_packages
-
-VERSION = (2, 4, 0)
-__version__ = '.'.join(map(str, VERSION[0:3]))
-__description__ = '''⚡⚡⚡Fast, Lightweight, Pluggable, TLS interception capable proxy server
-    focused on Network monitoring, controls & Application development, testing, debugging.'''
-__author__ = 'Abhinav Singh'
-__author_email__ = 'mailsforabhinav@gmail.com'
-__homepage__ = 'https://github.com/abhinavsingh/proxy.py'
-__download_url__ = '%s/archive/master.zip' % __homepage__
-__license__ = 'BSD'
-
-if __name__ == '__main__':
-    setup(
-        name='proxy.py',
-        version=__version__,
-        author=__author__,
-        author_email=__author_email__,
-        url=__homepage__,
-        description=__description__,
-        long_description=open(
-            'README.md', 'r', encoding='utf-8').read().strip(),
-        long_description_content_type='text/markdown',
-        download_url=__download_url__,
-        license=__license__,
-        python_requires='!=2.*, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
-        zip_safe=False,
-        packages=find_packages(exclude=['tests', 'tests.*']),
-        package_data={'proxy': ['py.typed']},
-        install_requires=[
-            'typing-extensions; python_version < "3.8"',
-        ],
-        entry_points={
-            'console_scripts': [
-                'proxy = proxy:entry_point'
-            ]
-        },
-        classifiers=[
-            'Development Status :: 5 - Production/Stable',
-            'Environment :: Console',
-            'Environment :: No Input/Output (Daemon)',
-            'Environment :: Web Environment',
-            'Environment :: MacOS X',
-            'Environment :: Plugins',
-            'Environment :: Win32 (MS Windows)',
-            'Framework :: Robot Framework',
-            'Framework :: Robot Framework :: Library',
-            'Intended Audience :: Developers',
-            'Intended Audience :: Education',
-            'Intended Audience :: End Users/Desktop',
-            'Intended Audience :: System Administrators',
-            'Intended Audience :: Science/Research',
-            'License :: OSI Approved :: BSD License',
-            'Natural Language :: English',
-            'Operating System :: MacOS',
-            'Operating System :: MacOS :: MacOS 9',
-            'Operating System :: MacOS :: MacOS X',
-            'Operating System :: POSIX',
-            'Operating System :: POSIX :: Linux',
-            'Operating System :: Unix',
-            'Operating System :: Microsoft',
-            'Operating System :: Microsoft :: Windows',
-            'Operating System :: Microsoft :: Windows :: Windows 10',
-            'Operating System :: Android',
-            'Operating System :: OS Independent',
-            'Programming Language :: Python :: Implementation',
-            'Programming Language :: Python :: 3 :: Only',
-            'Programming Language :: Python :: 3',
-            'Programming Language :: Python :: 3.6',
-            'Programming Language :: Python :: 3.7',
-            'Programming Language :: Python :: 3.8',
-            'Programming Language :: Python :: 3.9',
-            'Programming Language :: Python :: 3.10',
-            'Topic :: Internet',
-            'Topic :: Internet :: Proxy Servers',
-            'Topic :: Internet :: WWW/HTTP',
-            'Topic :: Internet :: WWW/HTTP :: Browsers',
-            'Topic :: Internet :: WWW/HTTP :: Dynamic Content',
-            'Topic :: Internet :: WWW/HTTP :: Dynamic Content :: CGI Tools/Libraries',
-            'Topic :: Internet :: WWW/HTTP :: HTTP Servers',
-            'Topic :: Scientific/Engineering :: Information Analysis',
-            'Topic :: Software Development :: Debuggers',
-            'Topic :: Software Development :: Libraries :: Python Modules',
-            'Topic :: System :: Monitoring',
-            'Topic :: System :: Networking',
-            'Topic :: System :: Networking :: Firewalls',
-            'Topic :: System :: Networking :: Monitoring',
-            'Topic :: Utilities',
-            'Typing :: Typed',
-        ],
-        keywords=(
-            'http, proxy, http proxy server, proxy server, http server,'
-            'http web server, proxy framework, web framework, Python3'
-        )
-    )
diff --git a/tox.ini b/tox.ini
index 8fb4694b3d..891000542b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,8 +1,69 @@
 [tox]
 envlist = py35,py36,py37,py38
+isolated_build = true
+minversion = 3.21.0
 
 [testenv]
 deps =
     -rrequirements.txt
     -rrequirements-testing.txt
 command = pytest
+
+
+[dists]
+setenv =
+  PEP517_OUT_DIR = {env:PEP517_OUT_DIR:{toxinidir}{/}dist}
+
+
+[testenv:cleanup-dists]
+description =
+  Wipe the the `{env:PEP517_OUT_DIR}{/}` folder
+usedevelop = false
+skip_install = true
+deps =
+setenv =
+  {[dists]setenv}
+commands =
+  {envpython} -c \
+    'import os, shutil, sys; dists_dir = os.getenv("PEP517_OUT_DIR"); shutil.rmtree(dists_dir, ignore_errors=True); sys.exit(os.path.exists(dists_dir))'
+
+
+[testenv:build-dists]
+description =
+  Build non-universal dists and put them into
+  the `{env:PEP517_OUT_DIR}{/}` folder
+depends =
+  cleanup-dists
+isolated_build = true
+# `usedevelop = true` overrides `skip_install` instruction, it's unwanted
+usedevelop = false
+skip_install = true
+deps =
+  build >= 0.7.0, < 0.8.0
+passenv =
+  PEP517_BUILD_ARGS
+setenv =
+  {[dists]setenv}
+commands =
+  {envpython} -m build \
+    --outdir '{env:PEP517_OUT_DIR}{/}' \
+    {posargs:{env:PEP517_BUILD_ARGS:}} \
+    '{toxinidir}'
+
+
+[testenv:metadata-validation]
+description =
+  Verify that dists under the `{env:PEP517_OUT_DIR}{/}` dir
+  have valid metadata
+depends =
+  build-dists
+deps =
+  twine
+usedevelop = false
+skip_install = true
+setenv =
+  {[dists]setenv}
+commands =
+  {envpython} -m twine check \
+    --strict \
+    {env:PEP517_OUT_DIR}{/}*
diff --git a/version-check.py b/version-check.py
index e783a2a36c..27e2b30a67 100644
--- a/version-check.py
+++ b/version-check.py
@@ -11,7 +11,6 @@
 import sys
 import subprocess
 from proxy.common.version import __version__ as lib_version
-from setup import __version__ as pkg_version
 
 # This script ensures our versions never run out of sync.
 #
@@ -19,13 +18,6 @@
 #    installer file, but it only needs to match with lib
 #    versions if current git branch is master
 
-# setup.py doesn't import proxy and hence they both use
-# their own respective __version__
-if lib_version != pkg_version:
-    print('Version mismatch found. {0} (lib) vs {1} (pkg).'.format(
-        lib_version, pkg_version))
-    sys.exit(1)
-
 # Version is also hardcoded in README.md flags section
 readme_version_cmd = 'cat README.md | grep "proxy.py v" | tail -2 | head -1 | cut -d " " -f 2 | cut -c2-'
 readme_version_output = subprocess.check_output(